1. Field of the Invention
The present invention relates to a retainer device for a heat sink assembly, and particularly to a retainer device incorporating a crank to readily and securely retain a heat sink on a central processing unit (CPU).
2. Related Art
Heat sinks are often used to dissipate heat from CPUs of computers. The heat sinks can be attached to the CPUs in a variety of ways, such as by gluing or using clips. An example of a conventional heat sink assembly is disclosed in Taiwan Patent Application No. 89210547. A clip of such heat sink assembly comprises a pressing portion, two spring portions extending from opposite ends of the pressing portion, and two locking arms depending from distal ends of the spring portions for engaging with a connecting element such as a socket. However, the clip and the connecting element are separate parts. Storage and transportation of these separate parts increases cost.
In addiction, developments in integrated circuits have resulted in greater circuit density and complexity, thus increasing heat generated by operation of such integrated circuits within an electronic package. Therefore, bigger and heavier heat sinks are becoming increasingly necessary to efficiently remove the heat. Nowadays, strong resilient clips are often used to attach heat sinks onto electronic devices. Accordingly, the force required to keep a heat sink in place has also increased. Unfortunately, in assembly, operators must exert great manual force when attaching the clip to the socket or to the motherboard. Extra tools are often required for installation or removal of the clip. There is considerable risk that during use of such tools, nearby components such as a motherboard will be accidentally damaged.
Thus a retainer device that can conveniently and safely secure a heat sink is desired.
Accordingly, an object of the present invention is to provide a retainer device which can readily and securely attach a heat sink to a CPU.
Another object of the present invention is to provide a retainer device which does not require a tool when the retainer device is manipulated to attach/detach a heat sink to/from a CPU.
To achieve the above-mentioned objects, a retainer device for attaching a heat sink to a CPU comprises a retention module, a clamp, and a crank. The retention module has a rectangular base frame, and four posts extending upwardly from the base frame. The clamp has two spaced hinge portions pivotably received in two rearmost posts of the retention module. A hook depends from a front of the clamp. The crank has an offset pressing portion, two pivot arms extending from opposite ends of the pressing portion, and an operation rod extending perpendicularly from one end of one of the pivot arms. The pivot arms are pivotably received in two frontmost posts of the retention module, with the pressing portion being disposed between the frontmost posts. When the operation rod is rotated down toward the heat sink and locked at one of the rearmost posts, the pressing portion resiliently presses the hook of the clamp.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with the attached drawings, in which: